docs: def main():
      '''Calculate the depth of a liquid in inches using a HCSR04 sensor
         and a Raspberry Pi'''
  
      trig_pin = 17
      echo_pin = 27
      hole_depth = 31.5  # inches
  
      # Default values
      # unit = 'metric'
      # temperature = 20
      # round_to = 1
  
      # Create a distance reading with the hcsr04 sensor module
      # and overide the default values for temp, unit and rounding)
      value = sensor.Measurement(trig_pin,
                                 echo_pin,
                                 temperature=68,
                                 unit='imperial',
                                 round_to=2
                                 )
      raw_measurement = value.raw_distance()
  
      # Calculate the liquid depth, in inches, of a hole filled
      # with liquid
      liquid_depth = value.depth_imperial(raw_measurement, hole_depth)
      print("Depth = {} inches".format(liquid_depth))